Apparatus for forming oval structural high-carbon-steel tubes



Oct. 14, 1930. F. P. VINCENT 1,778,433

APPARATUS FOR FORMING OVAL STRUCTURAL HIGH CARBON STEEL TUBES OriginalFiled Aug. 18, 1922 2 Sheets-Sheet l INVENTOR $4 ATTORNEYS.

F. P. VINCENT Get. 14, 1930.

APPARATUS FOR FORMING OVALI STRUCTURAL HIGH CARBON STEEL TUBES OriginalFiled Aug. 18, 1922 2 Sheets-Sheet 2 INVENTOR 7 P \/M BY K sl w l.

M ATTORNEYS.

Patented Oct. 14, 1930 UNITED STATES PATENT OFFICE I FRANKIE. VINCENT,or ELYBIA, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, r STEEL AND TUBES,INC., 0]? CLEVELAND, OHIO, A CORPORATION OF OHIO APPARATUS FOR FORMING-OVAL STRUCTURAL HIGH-CARBON-STEEL TUBES Original application filedAugust 18, 1922, Serial No. 582,588. Divided and this appilcationfiledJune 23,

'. 1924. Serial No. 721,680.

My invention relates to apparatus for forming oval structuralhigh-carbon steel tubes and particularly to such apparatus for producingtubes of this character from sheet steelwhich contains a high percentageof carbon, the sheet steel being rolled into tubular form and thereaftercaused to take the shape of an irregular oval tube, the diameter ofwhich is preferably increased in at least one direction at someparticular point intermediate the ends of the tube.

An object of my present invention is to provide an improved apparatusfor so deforming a high carbon steel tube preliminarily formed of sheetmetal in' general cylindrical shape, whereby the inequalities in theform of the tube will be eliminated and the tube. be formed throughoutits length to give it a desired irregular oval form, the same being.accomplished by pressure applied to the'tube in a partlcular way andwithout the necessity of pre-heating the tube.

Another object of my invention is to provide a tube so formed that itwill have the maximum of rigidity at an intermediate portion so thatthey will be highly efiicient for the purpose of forming portions ofstructures such as bed spring side frame members and the like.

Another object of my invention is to provide means for forming-the tubehaving a general oval cross sectional shape with ends which aresubstantially circular, when this is desired, for the purpose of fittingattaching brackets having circular openings to the ends of the tubes,such,as for instance, bed spring side frame member end brackets.

This application is a division of my previously filed application,Serial No. 582,588 filed August 18, 1922.

My invention will be better understood by reference tothe accompanyingdrawing which illustrates a preferred embodiment of my invention. 7

Referring to the drawings- Fig. 1 shows a front elevational view of amachine embodying my invention;

Fig. 2 shows a side elevational view of the machine illustrated in F 1;

Fig. 3' shows a plan view, shortened, of

tube of Fig. 6 taken from a point at right angles to that of Fig. 6.

Fig. 8 shows an end View of the tube of Fig. 7.

Fig. 9 shows a perspective view of the die plates employed to compressthe tube ends of the irregular oval tubes of Figs. 6 and 7 intosubstantially circular cross sectional I shape.

Figs. 10 and 13 are different transverse sections taken on the tube ofFig. 6 at the points indicated in Fig. 6. Figs. 11 and 12 are differenttransverse sections of the tube taken at points indicated in Fig. 4.

Referring now to the drawings in all of which like reference charactersindicate like parts, at l, I show the frame of a press which embodiesthe principles of my invention. At

2, I show a lower jaw for the said press rigidly mounted therein, and at3, I show a reciprocating upper jaw for the press, at 4 I show a formingdie mounted on the upper surface of the lower jaw 2, and at 5 I show anupper forming die member secured to the upper or reciprocating press awon its under side, the two forming dies presenting their forming facestoward each other, and in the forming faces of each I providelongitudinally extending grooves 6 for the lower (lie, and 7 for theupper die, these grooves are preferably symmetrical in transversedimensions throughout the operating length of the die, and are eachpreferably formed as a part of a cylinder less than half a cylinder andare therefore parti-cylindrical in form.

The grooves 6 and 7, when the dies 4 and 5 are brought nearly, butpreferably not quite,

together by downward movement of: the upper reciprocating jaw carryingthe upper die, define an approximately oval opening extending the fulllength of the dies, the opening, however, being preferably normallysymmetrical with regard to lateral cross sections throughout its length,the opening comprising opposing portions each constituting somethingless than a half circle, such portions being brought nearly together.The opening under such conditions will also correspond closely to theoutside dimensions of the brazed tubes to. be operated upon, althoughthere will be a slight diflerence in that the vertical dimension of theopening under such a condition would be slightly less than such outsidedimensions.

The material for the tubes is rolled into sheets of high carbon steel ofthe requisite thickness and width, being rolled into tubular form, therolling giving the tubes a form substantially cylindrical, the diameterof the cylindrical tubes thus prepared being such that the tube whenflattened to make it take the desired oval shape as described inconnection with the latter steps of the process employed, will produce atube having the requisite major and minor cross-sectional axesdimensions;

The seams of the tubes thus prepared are now brazed, or the edges at theseam secured together in any other suitable way, but I prefer to brazesuch a seam, it not being necessary for the purpose for which I use suclength either beforeor after brazing, but I prefer to cut them to'lengthbefore the braz mg.

The brazed tubes, substantially of cylin- .'drical shape and of properlength, are now introduced into the press having the die plates 4 and 5as before described, the cylin drical tube being placed in the groove 6for preferably when the lower die plate 4 is being the loWer die plate.

Now, prior to the operation of the press, and before the press is usedto form these tubes of proper irregular oval shape, and

positioned on the jaw 2, I place preferably between the die plate 4 andthe lower jaw 2, near the ends of the jaw such as'at 10 and 11, sheetsof paper or like equivalent material for the purpose of proper thicknesssuch as paper having a thickness of .008 inches, so that the lower dieplate is supported at either end on the paper sheets and secured to thelower jaw 2 with the 'papersheets near the ends of the j aw, and betweenthe die and the j aw.

The cylindrical tube now being positioned as before described in thegroove in the lowermost die plate, the operator by operating the pressas by stepping on the pedal lever 8 will cause power from the motor 9operating through suitable gears to cause the jaw 3 to descendvertically to such a distance that the tube will be pressed between theupper and lower die grooves to such an extent that the pressure willslightly cause the lower die plate 4 and to a less extent, the upper dieplate 5, to yield at their intermediate portions so that the pressure onthe intermediate portion of the tube will be relieved relative to thepressures at the ends of the tube, and the difference in pressures willbe gradual, lessening from the ends of the tube towards the center ofthe tube.

I find that a tube so formed is thicker in the direction of its minoraxis at the middle portion than it is at the ends, though not so thickin the direction of its major axis, and that it is possible to securetubes of desired proper form having an enlarged'central portion whichwill be uniform, there being a practically negligible loss due to cullswhereby under previously known processes for making oval tubes fromsteel of this character, the large number of culls produced be used asbed spring side frame members,-

since due to their form whereby the thickness is greater at theirintermediate portions, they resist bending, and especially twistingstresses such as are incidental to the use of such side frame membersin' practice; these side frame members may besuitably attached .to theend frame members of a bed. spring,

such end frame members being of angle iron or other forms,-in anydesired Way, as by forming flanges on the ends of the tubes, or bybrackets having tube end receiving sockets and attaching flanges. y

In Figs. 6, 7, 8, 10 and 13, I illustrate a different form of irregularoval tube which may be produced by my invention. In this embodiment ofmyinvention, after the tube has passed through the processes as beforedescribed, the ends of the tubes are inserted between die plates 12 and13, Fig. 9, for a short distance, and the die plates are then broughttogether to compress the tube, the tube being so inserted that its majoraxis is in substantially a vertical plane, the cooperating grooves 14and 15 which compress the ends, of the tubes 16 and 17, Figs. 6, 7 and8,- are of substantially semi-circular cross'sectional sha e, and whenbrought nearly together, de ne a cylindrical opening, and'compress thetube ends into substantially cylindrical shape. y

This is of special advantage where it is desired to employ the oval formof tubes for rigidity in constructions such as bed spring side framemembers where the brackets for connecting the side member oval tubes, asproduced by my invention, to the bed spring frames, such bracketscommonly having cylindrical shaped sockets adapted to receive thecommonly employed cylindrical tubular bed spring side frame members.

Having thus described my invention as'it low metal articles thecombination with a pair of press jaws of two dies having cooperatingrecessed faces, one die carried by each jaw, one die having a flexibleportion and supports adapted to support said flexible die on the jaw atthe ends of said portion.

2. In a press for forming irregular oval high carbon steel tubes inwhich the minor axes increase in length towards thecentral portion ofthe tube, the combination with a pair of press aws, a pair of die platesfor the said jaws each having a parti-cylindrical groove-in its face,means for securing the said die plates on the jaws, spacing meansbetween one of the said die plates and its jaw near the outer ends ofthe said plate, said die plate being constructed of slightly resilientmaterial, whereby when the said jaws are brought to their nearestadjacent position, with a proper cylindrical high carbon steel tubeinterposed between the said die plate grooves, the pressure applied toopposite sides of the said tube will be greatest nearer the tube endsand less towards its central portion.

3. A pair of dies for forming irregular, hollow metal articles, thearticle contacting surfaces of which are normally substantiallycylindrical, one of said dies having a flexible portion and means tosupport the die so that said portion may flex in operation to permit the.formation of an article having varying cross sections.

4. In an apparatus for forming irregular, hollow metal articles, thecombination of a pair of dies having work receiving recesses of normallyuniform cross section, one of said dies having a flexible section andmeans for supporting the dies so that said section may flex during aforming operation whereby the space between the dies becomes of varyingcross section.

5. In a press for forming irregular, hollow articles of hard metal, thecombination with a pair of press jaws having means for moving themtoward and from each other,

of a pair of recessed dies one carried by each jaw, one of said diesbeing flexible, and supporting means supporting said die at the endsonly of the flexible portion.

6. A one-piece flexible transversely concave forming die.

7. In a press for forming irregular hollow metal articles without theuse of a mandrel or other filler, the combination with a pair of pressjaws of two recessed dies, one carried by each jaw, one die having aflexible portion and supporting means for supporting said last named dieon the jaw to permit said portion to flex under forming pressure.

8. A pair of dies for forming irregular hollow metal articles whileinteriorly unsupported, each having a normally partial cylindricalrecess in its working face, and one of the dies being flexible to permitthe space between the dies to vary as an article is formed.

9. An apparatus for forming hollow metal articles while interiorlyunsupported which comprises a pair of dies having normally straightcomplementary grooves, one of the dies being'flexible and means forsupporting said flexible .die to permit limited flexurc when formingpressure is applied thereto.

10. A pair of metal-forming dies having normally complementary recessedsurfaces,

- one of the dies being flexible and means for supporting said flexibledie to flex away from the other under forming pressure.

11. A pair of forming dies, one of which is flexible and resilient, thedies having normally complementary recessed adjacent surfaces, means forsupporting the flexible die at spaced points between which it may flexaway-from the other, and means for limiting said flexure.

12. A pair of forming dies having normally complementary recessedadjacent surfaces, one of which dies comprises a flexible beam, andsupports therefor permitting the beam to bend away from the other die atits unsupported points under forming pressure.

In testimony whereof I hereunto aflix my signature this 17th day ofJune, 1924.

FRANK P. VINCENT.

